Grabby the Claw - a quick calibration test for 3D printed action figures!
Description
PDFIntroducing Grabby the Claw!
This model is designed to use all of the main connection types that you'll find in my 3D printable action figures.
It uses only a few grams of filament, and prints in about half an hour on modern printers.
That means it's a great way to dial in your settings and troubleshoot problems on a small scale, before committing to one of my bigger designs.
Plus, your feedback will help me make better designs in the future!
Before we begin
This is one of my fastest and easiest prints, but I still recommend that you at least have a satisfactory Benchy under your belt before diving into jointed figures like this one. The troubleshooting guide in this description focuses on the issues I see most often with my models - it's not a comprehensive guide to tuning your printer in general.
The parts are offered in two styles: one file with a full set of separate parts, and one with the parts connected on a runner (or kit card). If you want to work with individual parts, your slicer should be able to split the STL into separate objects.
 |  |
| Parts | Runner |
Print settings
Parameters not listed can stay at your slicer's default value.
| Filament type | Best results: ABS, ASA Also good: PETG, PCTG PLA is not recommended. |
| Layer height | 0.15mm |
| Infill | 15% |
| Supports | none |
| Perimeter generator | Arachne |
| Additional settings | ☑ Print external perimeters first |
Why no PLA?
PLA has a high tendency to creep. This means that the material relaxes over time, making the joints go “floppy.” It's also quite stiff, and brittle, leading to sore fingers and broken parts.
Feel free to try it for yourself if you don't believe me!
Assembly
If you printed the “runner” version, start by snapping the parts off of the runner. The “gates” where the runner contacted the parts can be cleaned up with a hobby knife.
All parts should snap fit firmly into place as shown without tools or glue.
If any connections take more than a moderate amount of force to come together, stop and look at ways to improve the fit. There's no need to push until your fingers bleed, please!
Troubleshooting
Please note that this is not a comprehensive guide for fixing print issues - there are better resources for that already. Instead, this chart focuses on those issues that I see most often with my designs in particular.
| Problem | Possible cause(s) | Solution(s) |
|---|---|---|
| Parts detach from the bed during printing | Print surface is not clean | Clean your build plate with dish soap and warm water |
| Avoid touching the build plate with your bare hands | ||
| Parts are knocked off by nozzle motion | Clean the nozzle with a brass brush to remove clumped filament | |
| Tune retraction settings to reduce clumping/stringing | ||
| Reduce printing speed - especially in the first layer | ||
| Avoid using “self crossing” infill patterns like Grid or Cubic | ||
| Print bed needs more adhesion | Apply a light coat of liquid glue to the build plate | |
| Make sure you are using a print bed that is appropriate for your filament type | ||
| Parts need more surface area to stick to bed | Add a brim to the parts in your slicer | |
| Use the “runner” version with all parts linked together | ||
| Residue from incompatible materials | Clean your build plate when switching between filament types (e.g. from PLA to PETG), or use a dedicated build plate for each material type | |
| Parts have extra strings or blobs of filament | Filament oozes when not extruding | Ensure that your filament is dry |
| Tune retraction settings | ||
| Use a heat gun to remove stringing | ||
| Overhang perimeters are detaching | Turn off “print external perimeters first” | |
| Poor quality at the top of small parts | Insufficient cooling of small layers | Increase cooling fan speed |
| Print more parts at a time | ||
| Print another model at the same time (it should be at least as tall as the problem parts) | ||
| Parts don't fit / are too tight / take too much force to assemble | Printed perimeters are oversized | Tune extrusion multiplier (make it smaller) |
| Apply XY size compensation (try +.05mm to start) | ||
| Print external walls first | ||
| Sand or file the parts for more clearance (wear a respirator, plastic dust is bad for you) | ||
| Material is too stiff | Use a more flexible material (PETG/PCTG) | |
| Parts are out of tolerance due to small printer variations | Print the parts larger to reduce the proportional effect of printer variations (try 150%) | |
| Parts are warping during printing | Add a brim to the parts | |
| Keep printer out of drafty areas | ||
| Print in an enclosure | ||
| Parts assembled incorrectly | Check the instructions for the correct parts and orientation | |
| Parts printed at a size much larger than default (>300%) | Use a more flexible material (e.g. a TPU blend) | |
| Parts are too loose (immediately after assembling) | Printed perimeters are undersized | Tune extrusion multiplier (make it bigger) |
| Apply XY size compensation (try +.05mm to start) | ||
| Disassemble the joint and apply a thin coat of nail polish or superglue to the interface, let it dry, and reassemble | ||
| Disassemble the joint and add a small amount of poster putty (blu-tack) to the interface, then reassemble | ||
| Parts are too loose (a while after assembling) | Material is subject to creep | Avoid materials like PLA with high creep levels (ASA has the best resistance to creep in my experience) |
| Parts break when assembled | Brittle filament | Ensure filament is dry, properly stored, and not too old |
| Use a more flexible material (PETG/PCTG) | ||
| Parts are too small to assemble | I mean they are pretty small, I'll give you that | Print larger! You should be able to scale up to at least 250% without issues. |
| I printed everything in PLA and it seems fine! | Creep hasn't set in yet | The main problem with PLA is creep, which happens over time. Check back in a week or two and Grabby won't be feeling so good. If you manage to find a brand of PLA that doesn't creep, I'd love to hear about it! |
| Made my fingers BLEED when I put it together! | Parts are too tight, see above | It shouldn't hurt to put this together! Take a step back and look at how to improve the fit to require less force. |
| My problem isn't on this chart | Are you sure? | Better double check! |
| Yes, I'm sure | Take clear pictures of the problem and post them in the comments with as much information as you can. I can't respond to every DM. Posting your issue publicly invites the community to help, and documents the solution for people in the future who might have the same problem. |
I welcome feedback and suggestions of how to improve these 3D printable joints. But please keep it constructive :)
License
This is a test file meant for personal use, so I have uploaded it on a more restrictive license for now.
Remixing is not allowed. Sit tight though, I am working on more guides to designing your own articulated figures.
Commercial use is not allowed. If you would like to sell prints of this model, please join one of the Seller License tiers of my Printables Club.
Thanks, and happy printing!
Tags
Model origin
The author marked this model as their own original creation.
